Decision support (i.e., alerts and reminders) at the time of medication prescribing has been shown to be an effective method for reducing potential medication errors for inpatients, but much less is known about the effects in the outpatient setting. Using qualitative methods to inform our work, medication safety decision support and provider education interventions were designed to improve the use of medications in ambulatory care. This paper presents the study rationale, design, development, and implementation of the interventions. We include a summary of the qualitative findings, including usability testing of the decision support, and we describe how the qualitative findings enhanced the intervention design. We also describe our approach to clinician recruitment. We enumerate limitations of the existing electronic medical record to accommodating recommendations from the qualitative work and usability testing. Our qualitative interviews suggest that clinicians prefer decision support alerts that are clear, concise, and easy to navigate, with minimal information in the alert text. In usability testing, we found that decision support alerts are followed less often when they appear at inappropriate times in workflow, are difficult to read, add to time pressure, and are canceled before being fully read. Our deliberate approach to clinician recruitment for the educational sessions achieved an impressive attendance rate of 85 percent. This study shows that careful consideration of alert design and provider education is critical. Future work will examine the effectiveness of the decision support and whether our educational intervention improves physician response.